Back to EveryPatent.com
United States Patent |
5,690,406
|
Furukawa
,   et al.
|
November 25, 1997
|
Control method for microfilm image reader
Abstract
A control method of a microfilm image reader is provided for reducing the
amount of image data to be transferred from a scanner to a host computer,
making the transfer time short and hence lengthening the free time of a
bus, reducing the storage capacity needed for storing the image data, and
simplifying the operation procedure by omitting the process of eliminating
the black frame portion when printed out. The host computer supplies the
scanner with a window parameter containing a range of reading area, and
the scanner detects only an image area from all the reading area to
transfer image data of the detected image area to the host computer
together with attribute information containing the size of the image area.
The attribute information may be managed by a header system, and data on a
print position of the target image may be contained in the attribute
information.
Inventors:
|
Furukawa; Takao (Tokyo, JP);
Hashimoto; Michinori (Kanagawa, JP)
|
Assignee:
|
Fuji Photo Film Co., Ltd. (Kanagawa, JP)
|
Appl. No.:
|
668824 |
Filed:
|
June 24, 1996 |
Foreign Application Priority Data
Current U.S. Class: |
353/25; 353/26A; 353/27A |
Intern'l Class: |
G03B 021/14 |
Field of Search: |
353/25,26 R,26 A,27 R,27 A
358/452,453
|
References Cited
U.S. Patent Documents
4745489 | May., 1988 | Kashiwagi et al. | 353/26.
|
4864149 | Sep., 1989 | Matsumoto | 353/26.
|
5416605 | May., 1995 | Hideshima et al. | 353/26.
|
Primary Examiner: Dowling; William
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak & Seas, PLLC
Claims
What is claimed is:
1. A control method for a microfilm image reader, in which a scanner with a
line sensor reads an image in a retrieved frame specified by a command fed
from a host computer and transfers image data of the read image to the
host computer, comprising the steps of:
outputting a window parameter containing a range of reading area from said
host computer to said scanner;
detecting by said scanner only an image area from all the reading area
specified by the window parameter; and
transferring image data of the detected image area from said scanner to
said host computer together with attribute information containing the size
of the image area.
2. The method according to claim 1, wherein the attribute information is
managed by a header system, in which the attribute information is stored
as portion of the image data in the same memory location as the image data
and transferred together with the image data.
3. The method according to claim 1, wherein the attribute information
contains a print position of the image to be printed out.
4. The method according to claim 2, wherein the attribute information
contains a print position of the image to be printed out.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a control method for a microfilm image
reader, in which a scanner retrieves a target frame specified by a command
fed from a host computer, reads an image in the target frame and transfers
image data of the read image to the host computer.
2. Prior Art
A typical microfilm image reader includes a host computer and a scanner, in
which the scanner retrieves a target frame based on a command in
accordance with a SCSI standard (hereinafter, referred as a SCSI command),
which is sent from the host computer to the scanner, and reads an image in
the target frame to be transferred to the host computer.
The host computer sets a range of a frame containing an image, i.e., sets a
range of reading area as a window parameter in the scanner before sending
an instruction for image-reading operation to the scanner. Assuming that
the range of the frame to be read is set in a range of m.times.n pixels in
the X-Y coordinate system, the scanner will read the image in the range of
m.times.n pixels and transfer image data of the read image to the host
computer. The image data is transferred to the host computer together with
an attribute information thereof.
The attribute information contains a retrieval key, a format of the image
data and the like, which is made into a table in a predetermined form. The
attribute information is managed by either a header system or a directory
system. The header system is used to store, in the same memory location or
memory area, the image data and the attribute information thereof that is
considered as a portion of the image data, and to transfer the image data
and the attribute information. The directory system is used to file the
attribute information individually so that the attribute information of
the image data can be memorized and managed separately from the image
data.
Each frame recorded on a microfilm includes an original image of a document
and a black frame portion surrounding the image. When developing or
printing a negative film into a positive, there exists an area of a black
frame portion (hereinafter, also referred simply as a black frame)
surrounding the original image. Since reading of the black frame is not
required, a conventional system generally performs preliminary scanning
throughout the full range of the image (reading area range) to detect the
black frame before performing real scanning of a true or actual image area
except the black frame so that only the image in the actual image area can
be read and transferred to the host computer.
FIG. 9 is a simplified diagram showing a conventional system for
transferring image data. In FIG. 9, a reference numeral 1 denotes the full
range of the image to be read, i.e., the reading range in the size of
m.times.n pixels. The size (m.times.n) is set by the host computer as a
window parameter in the scanner prior to the scanning operation. A
reference numeral 2 denotes a true or actual image area, i.e., an original
image of a document with the size of M.times.N pixels. Surrounding the
image area 2 is a black frame 3.
When the actual image area 2 is read by the scanner, the image data of the
image area 2 is transferred to the host computer together with its
attribute information. Since the attribute information used herein
contains data on the size of the reading area range 1 of a frame
corresponding to m.times.n pixels, a memory such as a buffer memory in the
scanner has to reserve a storage capacity for an area of m.times.n pixels.
The image data is transferred as data of m.times.n pixel size by adding
white area data subsequent to the image data of the actual image area 2
corresponding to M.times.N pixel size. The host computer thus memorizes
the image data, as shown in FIG. 9, such that the corner of the actual
image area 2A is shifted to the zero point of the full reading range 1A of
a frame, and the remaining area is made white or blank.
In such a conventional image data transfer system, although the actual
image area 2A is smaller than the area (reading area range) 1A set with
the window parameter, the image data of the same m.times.n size as the
area 1A is transferred by applying the white area data to all the area
(corresponding to the black frame 3) other than the actual image area 2A .
The unnecessary white area data is thus transferred to the host computer,
and this results in an increase of transfer time, thereby reducing the
free time of a bus (SCSI interface) which provides communication between
the host computer and the scanner. Another problem also arises that a
large storage capacity of the host computer is required for storing such
image data. Further, since the image data fed in the host computer
contains data of the white area to which the black frame was converted,
the white area data corresponding to the black frame must be eliminated
when supplying the image data to an output device such as printer.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a control method for a
microfilm image reader, in which the amount of image data to be
transferred from a scanner to a host computer can be reduced to make the
transfer time short and hence, lengthen the free time of a bus (bus free).
The storage capacity of the scanner as well as the host computer needed
for storing the image data can be reduced, and the operation procedure can
be simplified by omitting the process of eliminating the black frame
portion required when printed out.
The object of the present invention is attained by the provision of a
control method for a microfilm image reader, in which a scanner with a
line sensor reads an image in a retrieved frame specified by a command fed
from a host computer and transfers image data of the read image to the
host computer, comprising the steps of:
outputting a window parameter containing a range of reading area from said
host computer to said scanner;
detecting by said scanner only an image area from all the reading area
specified by the window parameter; and
transferring image data of the detected image area from said scanner to
said host computer together with attribute information containing the size
of the image area.
The attribute information may be managed by a header system, and data
indicating a print position of the target image may be contained in the
attribute information.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages and further description will now
be discussed in connection with the drawings, in which:
FIG. 1 is a schematic diagram showing a microfilm image reader system to
which an embodiment of the present invention is applied;
FIG. 2 is a block diagram showing a general structure of the system in FIG.
1;
FIG. 3 is a perspective view illustrating an inner arrangement of a scanner
used in the system in FIG. 1;
FIG. 4 is a flowchart showing operation of the embodiment;
FIG. 5 is a simplified diagram showing an image data transfer system of the
embodiment according to the present invention;
FIG. 6 is a schematic diagram explaining operation procedure of the
embodiment;
FIG. 7 is a diagram showing a structure of a window parameter;
FIG. 8 is a diagram showing a header structure of image data; and
FIG. 9 is a simplified diagram showing a conventional system for
transferring image data from a scanner to a host computer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a reference numeral 10 denotes a host computer,
which may be a personal computer or a work station. A key board 12 and a
printer 14 are connected to the host computer 10. Reference numeral 16
designates a scanner for retrieving a target frame recorded on a microfilm
and reading (scanning) an image in the target frame. The scanner 16 is
placed inside a MIS (Microfilm Install Unit) 24 described later.
The scanner 16 is then connected to the host computer 10 through a bus
(BUS) 18 in accordance with a SCSI standard. That is, the connection
between the host computer 10 and scanner 16 is established by a SCSI
interface. The scanner 16 includes a microfilm control unit (hereinafter,
also referred as MCU in this specification and appended drawings) 20 and a
roll-film retrieval unit (hereinafter, also referred as RRU) 22.
The MCU 20 is provided with a microcomputer for controlling retrieval
operation of the RRU 22 as well as for reading an image in a retrieved
frame while moving a line sensor and storing image data of the read image
in a memory 20A such as a DRAM. The RRU 22 retrieves a desired frame while
feeding a roll of microfilm.
The microfilm install unit (MIS) 24 stores a large number of microfilm
cartridges and selects a desired cartridge to load the RRU 22 of the
scanner 16. When the MCU 20 has specified a cartridge containing a target
frame to be retrieved, if the cartridge is not being loaded into the RRU
22, the MIS 24 will operate to replace a cartridge currently loaded in the
RRU 22 by the cartridge containing the target frame.
The MIS 24 has a rectangle case 50, and cartridge shelves 52 are provided
inside the case 50 for storing a large number of microfilm cartridges 54
so that a desired cartridge can be slid in or out from the front of the
corresponding shelf 52. On the front face of the case 50, guide rails 56
(56a, 56b, 56c, 56d) are fixed along the four sides. A horizontal rail 58
is guided along the opposite two guide rails 56a, 56c to move up and down,
whereas a vertical rail 60 is guided along the opposite two guide rails
56b, 56d to move sideways.
The horizontal rail 58 and the vertical rail 60 move in vertical and
lateral directions, respectively, at right angles to each other, and a
cartridge carrier 62 is slidably attached to the rails 58, 60 at the
intersection of the two rails 58, 60. The horizontal rail 58 is fixed to a
belt 64 tightly wound around a pair of pulleys located near both ends of
the guide rail 56a, whereas the vertical rail 60 is fixed to a belt 66
tightly wound around a pair of pulleys located near both ends of the guide
rail 56d. The belts 64, 66 are moved and positioned by motors 68, 70,
respectively, each motor 68, 70 being coupled to a corresponding pulley.
Thus, the horizontal rail 58 and the vertical rail 60 are moved
individually by the motors 68 and 70, so that the cartridge carrier 62 can
be shifted to a proper position. The cartridge shelves 52 and the scanner
16 are located within a movable range of the cartridge carrier 62. For
example, the scanner 16 is placed in the right corner of the lower portion
within the movable range of the cartridge carrier 62.
The cartridge carrier 62 picks up a desired cartridge 54 from a cartridge
shelf 52 and carries it to the scanner 16. After the retrieval and reading
operation, the cartridge carrier 62 receives a currently loaded cartridge
from the scanner 16 at the end of the retrieval and returns it to a
predetermined position on the corresponding cartridge shelf 52.
Referring next to FIG. 3, an inner arrangement of the scanner 16 will be
described. The scanner 16 includes the MCU 20 and the RRU 22 as mentioned
above. The scanner 16 has a longitudinal cabinet 72, and the MCU 20 and
the RRU 22 are provided inside the cabinet 72. The MCU 20 is constituted
with a microcomputer and mounted on the bottom of the cabinet 72.
Hereinbelow, a description will be made of the RRU (roll-film retrieval
unit) 22.
In the cabinet 72, a feed reel driving unit 74 and a take-up reel driving
unit 76 are arranged in the upper front portion and lower front portion,
respectively. When a cartridge 54 is inserted into a cartridge loading
port 78, the feed reel driving unit 74 automatically moves the cartridge
54 and engages a feed reel with a rotating shaft of the feed reel driving
unit. Then, the feed reel driving unit 74 pulls out a head lead of a roll
film 80 loaded in the cartridge 54 and feeds it downwardly to guide it to
a take-up reel 82 in the take-up reel driving unit 76.
When viewing the scanner 16 in FIG. 3, the film 80 passes through the back
side of the empty space between the respective reel driving units 74, 76,
that is, the film 80 passes through at the inner backside as viewed from
the front of the cabinet 72, so that light source lamp 84 and condenser
lens 86 can be arranged in a space formed by a gap between the
reel-to-reel distance and the front panel of the cabinet 72.
In the cabinet 72, a line sensor unit 88 is also provided for reading a
projected image in a target frame by a line sensor. The line sensor unit
88 is integrated with a projection lens 90. More specifically, a
cylindrical section 92 for holding the projection lens 90 is integrally
formed with the case of the line sensor unit 88. The projection lens 90
mounted in the cylindrical section 92 is a fixed focus lens with a
magnifying power of approximately 2.
In the case of the line sensor unit 88, a movable plate 94 is provided on
the side opposite to the cylindrical section 92. The movable plate 94 is
slidably mounted along with a pair of guide rods (not shown) fixed to the
case, so that the movable plate 94 can reciprocate along a plane
perpendicular to an optical axis 96 and around the opening of the
cylindrical section 92.
Further, a belt 102 wound around pulleys 98, 100 is provided inside the
case in a position parallel to the reciprocating direction of the movable
plate 94, and one side of the movable plate 94 is fixed to the belt 102.
The belt 102 is driven by a stepping motor 104 through the pulley 100.
Thus, the movable plate 94 can be reciprocated on a plane perpendicular to
the optical axis 96 by rotating the stepping motor 104 in a forward or
reverse direction.
A CCD arrayed line sensor 106 is fixed on the movable plate 94 in a
direction perpendicular to the reciprocating direction of the movable
plate 94. It should be noted that the light-receiving surface of the CCD
line sensor 106 must correspond to a plane on which a projected image from
the projection lens 90 is focused.
The RRU (roll-film retrieval unit)22 is also provided with a blip mark
detection means (not shown) for detecting blip marks previously marked on
each frame of the film 80 as key points of the retrieval. The blip marks
are counted by a light-emitting element and a light-receiving element
arranged to provide a light path through the film 80.
The MCU (microfilm control unit) 20 thus controls the RRU 22 to search or
retrieve a target frame in accordance with the counted blip marks
corresponding to the target frame.
The host computer 10 outputs a "SET WINDOW" command through the bus 18 to
the MCU 20 to set a window parameter (step 200 in FIG. 6) in the MCU 20.
The window parameter consists of set items as shown in FIG. 7, i.e., a
window identifier, the resolution or the numbers of pixels in X and Y
axes, offset amounts in upper left sections of X and Y axes or the zero
point, a window width or a reading range of a frame (corresponding to area
1 or 1A in FIGS. 9 or 5), brightness, a threshold value, etc.
The MCU 20 executes predetermined processings such as to reserve a storage
area in the memory 20A on the basis of the parameter. After end operation
of such processings, the MCU 20 sends a complete signal through the bus 18
back to the host computer (step 202 in FIG. 6), and the host computer then
outputs a "SCAN" command to the MCU 20 (step 204).
The "SCAN" command contains an address of a target frame to be retrieved.
The MCU 20 starts retrieving the target frame immediately after receiving
the "SCAN" command (step 206). The RRU 22 is operated to select the target
frame from the microfilm while feeding the film. When no target frame is
recorded on the microfilm in the cartridge currently loaded in the RRU 22,
the MCU 20 sends a signal to the MIS 24 to replace the cartridge by
another one containing the target image (step 208). The cartridge is
replaced by a new one after the film is rewound into the cartridge.
After the target frame is found, the MCU 20 reads the full reading range of
a frame specified by the window parameter and detects the black frame 3
(preliminary scanning at step 210 in FIGS. 4 and 6; also see FIG. 5).
Coordinate data of the black frame 3 is input to the memory 20A and
written as attribute information in a header HD or footer FT shown in FIG.
8.
As shown in FIG. 8, the header HD contains a header identifier, image
widths m and n in the X and Y axes, and other attribute information. In
the embodiment, the footer FT is provided after the image data, in which
data of the black frame 3, i.e., data on the size of the actual image area
2 corresponding to M.times.N pixels is written. It should be noted that
the data on the size of the actual image area 2 corresponding to M.times.N
pixels may be written in the header HD.
The MCU 20 then moves the line sensor again and reads an image in the
actual image area 2 to memorize image data of the read image sequentially
in the memory 20A (real scanning at step 212 in FIGS. 4 and 6). The image
in the actual image area 2 is read by masking or eliminating the black
frame portion 3. When the image has been completely read after end
operation of the scanning, the MCU 20 sends a command complete signal
through the bus 18 to the host computer 10 (step 214 in FIG. 6).
The host computer 10 then outputs a "READ" command upon receipt of the
command complete signal (step 216 in FIG. 6). The MCU 20 receives the
"READ" command and transfers the header HD, the image data of the image
area 2 and the footer FT from the memory 20A to the host computer 10 (step
218 in FIGS. 4 and 6). After end operation of the data transfer, the MCU
20 sends the command complete signal to the host computer so that the host
computer 10 can start retrieving the next target frame (step 220 in FIG.
6).
By repeating the above-described operation procedure, a large number of
frames are sequentially retrieved, images in the respective retrieved
frames are read and the image data of the respective read images are
transferred to the host computer 10. Finally, the host computer 10
processes the image data in predetermined image processings (step 222 in
FIG. 4) and supplies the processed data to a printer 14 (step 224 in FIG.
4). The image data may be transferred to other computer or a storage
medium such as a magneto-optical disk.
In this embodiment, the size of the image data of the actual image area 2
is M.times.N pixels. The image data is transferred to the host computer 10
together with the header HD and the footer FT as one data group by adding
the header HD and the footer FT before and after the image data. Since
there is no need to rewrite the black frame portion 3 (see FIG. 5) into a
white area data and to transfer the rewritten data to the host computer
10, the amount of transfer data can be reduced, resulting in short
occupation time of the data bus 18 when the data is transferred.
In the header system, the image size of M.times.N pixels is included in
either the header HD or the footer FT. In contrast, in a directory system,
the size data may be contained in a file of the attribute information to
be transferred to the host computer 10 separately from the image data of
the read image. The present invention can be applied to such a case as
used in the directory system.
In the embodiment, although the attribute information on the data size of
the actual image area 2 (corresponding to M.times.N pixels) is transferred
to the host computer 10 together with the image data of the actual image
area 2, other data attributes may be set as attribute information together
with or instead of the attribute information on the size of the actual
image area. The following are examples of data attributes that can be set
as attribute information.
The first example sets a printing position in which the image data of the
true image area 2 is printed out (information of the image output
position). By setting such information, the image in the true image area 2
can be printed out in a correct or true position of a print paper.
The second example sets a strength parameter of a mask as attribute
information, the strength parameter required when an unsharped mask method
is used for an edge-emphasizing processing.
In the third example, a curve parameter of a look-up table for controlling
tone representation of the image is set as an attribute information. In
the look-up table, the pixel tone or density (input) is set for a
horizontal axis and the transformed pixel tone or density (output) is set
for a vertical axis so that a transformation characteristic between the
tones can be determined. The curve parameter is used to describe a curve
of the transformation characteristic.
The fourth example sets a size parameter of a mask as attribute
information. The mask size is used to determine a decision area required
when the image is processed by a spacial filtering.
The fifth example sets a density range parameter as attribute information.
By the density range parameter, a part of a read image within a
predetermined density range, which is set in a high density side and/or a
low density side, is converted to a constant density level.
The sixth example sets a dither pattern parameter as attribute information,
for binarizing multi-tone or multi-leveled gradation image data of the
read image using a dither method.
The seventh example sets a slice level (threshold value) for binarization
as attribute information, the slice level used for binarizing processing
an image which is photographed in an automatic exposure (AE) control
photometry for automatically measuring the light exposure of an image to
be photographed and automatically controlling the intensity of light
exposing the image. In the case the AE photometry is used, since the
exposure density remarkably varies depending on the type of a document
containing a target image, such as a map or an old document, it is
necessary to greatly change the slice level for binarizing multi-valued
density or half-tone data of the read image. Thus, the parameter needs
setting for changing the slice level in accordance with the exposure
density.
As described above, according to the present invention, the scanner detects
the black frame portion of an image and transfers image data for all the
area except of the black frame portion, i.e., transfers image data of the
actual image area to the host computer together with attribute information
containing the data size of the actual image area, so that the amount of
data to be transferred can be reduced, resulting in short transfer time.
Accordingly, occupation time of the bus required during the data transfer
is also reduced, and this is convenient for transferring other data
through the same bus.
Since the amount of image data to be stored in the memory of the scanner as
well as the host computer is also reduced, the storage capacity to be
allocated to the image data can be reduced. Further, the host computer is
not required to perform image processing to eliminate the black frame
portion from the entire image data to be transferred from the scanner to
the host computer, so that the operation procedure can be simplified.
Top